Matthew McCollough, M.D. April 9, 2009 University of Louisville

Transcription

1 Matthew McCollough, M.D. April 9, 2009 University of Louisville

2 List the differential diagnosis for pancreatic cysts Review the epidemiology Illustrate the types of cysts through case discussions Discuss radiographic and endoscopic imaging techniques Present guidelines for management

3 Pseudocyst Inclusion cyst (reactive) Serous cystadenoma (SCA) Mucinous cystic neoplasm (MCN) Intraductal papillary mucinous neoplasm (IPMN) Solid pseudopapillary tumor (SPT) Lymphoepithelial cyst Cystic endocrine neoplasm Cystic degeneration of solid tumors

4 Female predominance 4:1 Mean age of diagnosis is 54 years The prevalence of pancreatic cysts is 1.2% 10% of cysts are neoplastic One percent of pancreatic neoplasms are cystic They are typically asymptomatic and found incidentally on diagnostic imaging for other indications Spinelli KS, et al. Ann Surg 2004; 239:651. Fernandez-del Castillo C, et al. Surg Clin North Am 1995; 75:1001. Warshaw AL, et al. Ann Surg 1990; 212:432

5 Total cases = 300 Feldman: Sleisenger & Fordtran's Gastrointestinal and Liver Disease, 8th ed.

6 The initial evaluation focuses on differentiating cysts with malignant potential from those without Pseudocysts, inclusion cysts and SCA s are considered benign MCNs, IPMNs, SPT s, and solid tumors have malignant potential

7 A pseudocyst represents a collection of pancreatic juices that has extravasated from the ductal system due to inflammation or obstruction Lack an epithelial lining (hence the term pseudo ) Extravasation is due to inflammation and/or obstruction Clues that favor pseudocysts include history of acute or chronic pancreatitis or previous abdominal trauma

8 No septa, loculations, solid components, or wall calcifications Hypovascularity Cyst communicates with the ductal system (also characteristic of IPMN)

9 Pseudocyst: Anechoic, thick walled, rare sepations, regional inflammatory nodes Parenchymal abnormalities suggestive of chronic pancreatitis Sensitivity 94%, Specificity 85% SCA: Multiple microcysts (<3mm) within a cystic lesion Accuracy 92% - 96%

10 Helical CT with IV contrast (pancreas protocol) PET/CT MRCP ERCP Pancreatoscopy EUS with fine-needle aspiration

11 The critical decision is deciding which neoplasms need resection and which don t In general, cystic neoplasms are more indolent than pancreatic adenocarcinoma and resection can potentially cure

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14 Microcystic adenoma Women (80%), mean age 62 years Most occur in the body or tail (50% 70%) Associated with von Hippel-Lindau disease Composed of multiple thin-walled cysts lending to a honeycomb appearance Contains a simple, glycogen-rich cuboidal epithelium with a fibrotic or calcified central scar

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16 Can be diagnosed by CT in 30% of cases; diagnostic criteria include: Spongy mass with a central sunburst calcification (10-20%) Microcysts enhance after contrast injection Larger cysts are seen on the periphery

17 Cystic fluid analysis Non-viscous Low CEA (<5 ng/ml) Yield <50% Considered benign Serous cystadenocarcinomas have been described but evidence is on the level of case reports and they constitute less than 1% of known cases

18 Symptomatic lesions may be resected, but observation is safe in asymptomatic individuals Risks of watchful waiting include: Hemorrhage Obstructive jaundice Pancreatic insufficiency Gastric outlet obstruction Some experts at high-volume centers recommend resection of ALL serous cystadenomas in medically fit patients

19 Cystic fluid revealed CEA 3 ng/ml No further imaging needed FNA is not required if the diagnosis is firm The patient elected to forgo surgery unless symptoms develop

20 Adverse Event Complication Rate (%) Pancreatitis Hemorrhage within the Cyst <1 Retroperitoneal bleeding <0.01 Infection <1

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23 Accounts for 44-49% of cystic neoplasms of the pancreas > 80% are in women, mean age 55 years May be 2 26 cm in maximum diameter Often located in the body or tail (66%) No communication with the pancreatic duct Composed of large compartments with thin septa that may contain an eccentric solid component

24 Mucin-producing columnar epithelium Highly cellular ovarian stroma

25 341 patients with pancreatic cystic lesions underwent EUS-FNA CEA, CA 72-4, CA 125 CA 19-9, and CA 15-3 where analyzed 112 patients underwent surgical resection 68 MCN, 7 Serous, 27 inflammatory, 5 endocrine, 5 other Brugge WR, et al. Gastroenterology 2004; 126:1330.

26 Conclusion: CEA of 192 ng/ml was the most accurate for differentiating mucinous from non-mcn Sensitivity 73%, Specificity 84% No combination of tests was more accurate than CEA alone Note: Study did not differentiate MCN from IPMN Brugge WR, et al. Gastroenterology 2004; 126:1330.

27 Pseudocyst Serous Cystadenoma Mucinous Cystadenoma IPMN CEA Low/Variable Low High High CA 19-9 High/Variable Variable Variable Variable CA 72-4 Low/Variable Low High High CA 15-3 Low Low High Low/Variable Amylase High Low/Variable Low Variable High Cytology Neutrophils and macrophages PAS+ cuboidal epithelium with glycogen Mucin+ Columnar cells with variable atypia Mucin+ Columnar cells with variable atypia Cytologic accuracy is around 50% and even less in smaller cysts Patwardhan, JL. Practical Gastro 2008;Nov,11-25

28 Pseudocysts are virtually excluded with amylase <250 and CEA >800 Mucinous cysts can be excluded with a CEA <5 and CA 19-9 <37 Fluid analysis cannot differentiate MCN from IPMN

29 Cystic fluid DNA Molecular studies have shown the presence of K-ras, tumor suppressor gene mutations, and telomerase activity in mucinous cystic lesions Khalid A, et al. Gastroenterol Hepatol 2005,

30 Case series of 61 patients with MCN Final histopathologic diagnosis Wilentz RE, et al Am J Surg Pathol 1999; 23(11):

31 Management of surgical candidates: Head lesion pancreaticoduodenectomy Body/tail lesion distal pancreatectomy + splenectomy

32 5 year follow up of a mucinous cystic lesion Brugge WR. Digestiv and Liver Disease. 2008;40:11,

33 FNA showed cystic CEA of 812 ng/ml Cytology showed mucin + columnar cells, no malignant cells Patient underwent distal pancreatectomy with a good surgical outcome

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35 Synonyms: Mucinous ductal ectasia Intraductal mucin-producing tumor Intraductal cystadenoma Pancreatic duct villous adenoma Intraductal papillary neoplasm The term IPMN was officially adopted in 1996 by the World Health Organization and the Armed Forces Institute of Pathology

36 Found in male > female during the 6 th to 7 th decade Seventy-five percent of patients are symptomatic Weight loss, abdominal pain, acute/chronic pancreatitis, nausea/vomiting, fever, diarrhea, diabetes, steatorrhea, jaundice Located more often in the head of the pancreas residing in the main duct or its side branches Ohashi K, et al. Prog dig Endosc 1982;20:348.

37 Premalignant lesions characterized by proliferation of mucinous epithelium with ductal and cystic dilation Often exhibit papillary growth with mucin production Lack ovarian-type stroma that characterizes mucinous cystic neoplasms Invasive neoplasm is discovered in 20%-50% of IPMNs at the time of surgery Hruban RH, et al. Am J Surg Path 2004;28: Lim JH, et al. Radiographics 2001;21: Sohn TA, et al. Ann Surg 2004;239:

38 Mucinous epithelium that lacks ovarian-stroma

39 A. Branch duct IPMN B. Diffuse main duct IPMN C. Segmental main duct IPMN D. Mixed IPMN Sahani DV, et al. Clinical Gastro and Hep 2009;7:

40 106 patients (76 proven) (30 probable) MD = 53, BD =53 Median follow-up 21 months Levy PJ Clin Gastroenterol Hepatol 2006;4:

41 Requires a dedicated pancreatic protocol technique Communication between branch duct lesions and main PD can often be seen, but lack of communication does not rule out IPMN Involvement of the main pancreatic duct often shows dilation of the duct and atrophy in the body/tail region

42 MRCP is better for small lesions (<3 cm) in showing ductal communication For main duct lesions, MRCP is better for showing small mural nodules

43 Patulous ampulla of Vater extruding mucus (20% 50%) Main Duct IMPN may show diffuse main duct dilation, mucinous filling defects, and a papillary tumor in main duct Branch duct lesions appear as a cluster of grapes that communicate with the main duct

44 Limitations of ERCP vs. MRCP Malignant duct obstruction Differentiating mucin globules vs. mural nodules Risks of the procedure

45 Direct visualization and biopsy

46 Good at showing internal septa, mural nodules, solid masses, vascular invasion, and lymph node metastases

47 Thick walls Thick septations Prominent mural nodules Lymph node and vascular invasion With EUS alone, it is very difficult to distinguish benign from malignant neoplasms in the absence of advanced disease

48 Limited yield in lesions smaller than 3 cm CEA and CA 72-4 cannot differentiate between types of mucinous lesions or presence of malignancy Five to 20% of mucinous lesions including adenocarcinomas do not contain elevated CEA levels

49 Proposed criteria for pancreatic resection in IPMN (1 or more of the following) 1. Symptoms attributable to the cyst (e.g., pancreatitis) 2. Dilation of the main pancreatic duct 3. Cyst size >3 cm 4. Presence of intramural nodules 5. Cystic fluid cytology suspicious or positive for malignancy Tanaka M, et al. Pancreatology 2006;6:17.

50 Sahani, DV, et al. Clinical Gastroenterology and Hepatology 2009;7:

51 Recurrence is rare after resection of noninvasive tumors Three year recurrence rates for invasive tumors ranged from 12% - 65% Patients with recurrent disease localized to the pancreas benefit from complete pancreatectomy Salvia R, et al. Clinical Ann Surg 2004; 239:678. D'Angelica M, et al. Ann Surg 2004; 239:400.

52 Actuarial survival in patients with invasive and noninvasive IPMN Salvia R, et al. Ann Surg 239:678, 2004.)

53 Sahani, DV, et al. Clinical Gastroenterology and Hepatology 2009;7:

54 The patient had main duct involvement with mural nodules that would require total pancreatectomy Given his poor health status and the risk of the procedure, he elected for palliative care referral

55 Synonym: papillary cystic neoplasm Least common of pancreatic cystic neoplasms Women in 2 nd 3 rd decade located in pancreatic body and tail Fluid is often bloody and necrotic

56 Cytology shows branching papillae with myxoid stroma Stains positive for vimentin and ά-1-antitrypsin Locally aggressive invading adjacent structures Treament: Surgical resection if possible

57 Rare Mostly men, any age, asymptomatic Contain keratinizing squamous epithelium surround by lymphoid tissue T2-weighted MRI intracystic keratin

58 EUS heterogeneous, hyperechoic cyst FNA epithelial cells, lymphocytes, keratin debris, anucleate squamous cells, and multinucleated histiocytes

59 May exhibit clinical features of solid endocrine tumors Unilocular cyst Fluid is thin and clear Cytology shows monomorphic endocrine tumor cells Stains positive for chromogranin and synaptophysin Potentially malignant

60 Solid pancreatic tumors may undergo cystic degeneration including: Islet cell tumors Ductal carcinoma Acinar cell cancer Islet cell tumors may be indistinguishable from MCN or side branch IPMN Cytology may be helpful to differentiate

61 Small cysts can be malignant A series of sub-2 cm cysts 20% malignant 45% had malignant potential CEA is not predictive of malignancy Fernandez-del Castillo C, et al. Arch Surg 2003;138:427-34

62 Recognition of pancreatic cystic neoplasms is on the rise Diagnostic evaluation focuses on determining the malignant potential of cysts Management is driven by symptoms, the certainty of the diagnosis and the surgical fitness of the patient

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64 Author # cases CEA ng/ml Cyst Sensitivity % Specificity % Hammel <5 for SCA Hammel >20 for MCN from SCA >300 for MCN from pseudocyst Hammel >400 for MCN <4 for SCA Brugge >192 for MCN Adapted from ACG Practic Guidelines. AJG 2007;